1. Field of the Invention
The present invention relates to iontophoretic drug delivery systems for transdermally delivering a drug or medicine to a patient, and more specifically relates to a connector which electrically couples a drug-containing patch and a controller.
2. Description of the Prior Art
Iontophoresis may be defined as the non-evasive transdermal delivery of medicine/chemicals. This process has become an increasingly popular and effective method for the delivery of pharmaceuticals. In practice, the process of iontophoretic drug delivery is typically achieved by placing a medicine (in ionic form) on a carrier, and attaching the medicine-containing carrier upon a patient's skin. A pair of electrodes are placed in contact with the patient's skin and in close proximity with the carrier. An electric current is provided by the electrodes through the skin. The electric current causes the ionic medicine to diffuse from the carrier of the patch through the skin.
Delivery of a drug to a patient iontophoretically may be best accomplished in a number of ways, such as at a constant rate over a long time period, or periodically at regular intervals. In order to ensure proper drug delivery, it is necessary for the drug-containing carrier to be maintained in contact with the patient's skin. The iontophoretic delivery system may include a drug-containing carrier such as an adhesive patch. The system may also include a source of electric power which is connectable to the patch for providing the proper electric current for transmission of the drug in accordance with the desired rate of delivery.
The electrical connections between the patch and controller in known drug delivery devices typically utilize resiliently biased conventional mechanical contacts. With this type of connection, wear and corrosion on the resiliently biased contacts from the repeated cycling of connection and removal of the patch with respect to the controller and from environmental conditions may have a deleterious effect on the contacts. The deleterious effects include the abrupt cessation of current delivery to the patch due to the "making and breaking" between the contacts. These current transients which may be produced may result in an uncomfortable sensation to the patient.
In transdermal delivery devices where the controller is detachable from the patch, the materials utilized on the patch and controller for electrical coupling must be electro-chemically compatible with one another. Otherwise, electrolysis and corrosion may result affecting the quality of the electrical connection. This may result in electrical noise or current transients which may cause patient discomfort.